TY - JOUR
T1 - Polarization in groups of Bayesian agents
AU - Pallavicini, Josefine
AU - Hallsson, Bjørn
AU - Kappel, Klemens
PY - 2021/1
Y1 - 2021/1
N2 - In this paper we present the results of a simulation study of credence developments in groups of communicating Bayesian agents, as they update their beliefs about a given proposition p. Based on the empirical literature, one would assume that these groups of rational agents would converge on a view over time, or at least that they would not polarize. This paper presents and discusses surprising evidence that this is not true. Our simulation study shows that these groups of Bayesian agents show group polarization behavior under a broad range of circumstances. This is, we think, an unexpected result, that raises deeper questions about whether the kind of polarization in question is irrational. If one accepts Bayesian agency as the hallmark of epistemic rationality, then one should infer that the polarization we find is also rational. On the other hand, if we are inclined to think that there is something epistemically irrational about group polarization, then something must be off in the model employed in our simulation study. We discuss several possible interfering factors, including how epistemic trust is defined in the model. Ultimately, we propose that the notion of Bayesian agency is missing something in general, namely the ability to respond to higher-order evidence.
AB - In this paper we present the results of a simulation study of credence developments in groups of communicating Bayesian agents, as they update their beliefs about a given proposition p. Based on the empirical literature, one would assume that these groups of rational agents would converge on a view over time, or at least that they would not polarize. This paper presents and discusses surprising evidence that this is not true. Our simulation study shows that these groups of Bayesian agents show group polarization behavior under a broad range of circumstances. This is, we think, an unexpected result, that raises deeper questions about whether the kind of polarization in question is irrational. If one accepts Bayesian agency as the hallmark of epistemic rationality, then one should infer that the polarization we find is also rational. On the other hand, if we are inclined to think that there is something epistemically irrational about group polarization, then something must be off in the model employed in our simulation study. We discuss several possible interfering factors, including how epistemic trust is defined in the model. Ultimately, we propose that the notion of Bayesian agency is missing something in general, namely the ability to respond to higher-order evidence.
KW - Bayesian updating
KW - Epistemic rationality
KW - Epistemic trust
KW - Group polarization
KW - Higher-order evidence
UR - http://www.scopus.com/inward/record.url?scp=85055968291&partnerID=8YFLogxK
U2 - 10.1007/s11229-018-01978-w
DO - 10.1007/s11229-018-01978-w
M3 - Journal article
AN - SCOPUS:85055968291
VL - 198
SP - 1
EP - 55
JO - Synthese
JF - Synthese
SN - 0039-7857
ER -